K classing cover final spread pdf 1 9/17/2013 5: 28: 32 pm

Instrument Standards

Instrument standards are cottons 

used for instrument calibration 

and verification. These 

standards include Universal HVI 

Calibration cotton, Extra-Long 

Staple (ELS) Calibration cotton, 

Universal HVI Micronaire 

Calibration cotton, and Universal 

HVI Cotton Color and Cotton 

Trash Standards. These standards 

serve the USDA and most cotton 

organizations worldwide as 

the basis for instrument cotton 

classification. 

Examples of Universal Color Standards 

and Micronaire Standards for high  

volume instrument calibration.

USDA maintains fifteen physical Upland Grade Standards and six physical American 

Pima Grade Standards. 

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Cotton selected for use in instrument calibration must pass rigorous 

screening procedures. As a first step, USDA conducts an extensive 

search in the National Database for uniform lots of cotton from the 

current crop that have fiber properties appropriate for their intended 

use. Candidate bales are purchased from producers and retested through 

a rigorous value-establishment process to determine whether they meet 

the strict certification requirements set for calibration cotton.